mc44bc375u Freescale Semiconductor, Inc, mc44bc375u Datasheet - Page 12

• Manufacturer Part Number: mc44bc375u
• Description: Pll Tuned Vhf Channel 3 / 4 Audio / Video Modulator
• Manufacturer: Freescale Semiconductor, Inc

Table 9. Performance Measurement Test Set-Ups (continued)
MC44BC375U
12
Audio: 1.0 KHz, adjustable level
Video: EBU Color Bars
This is measured using a Demodulator in B/G
and an Audio Analyzer at 1.0 KHz. The output
level of the Audio analyzer is varied to obtain
a Modulation Deviation of 25 KHz indicated
on the AMFS Demodulator.
Pin 1: CHS
Pin 2: PSS
Pin 16: SFS
Pin 9: Psave/LO
Pin 3: LOP
Pin 4: XTAL
Pin 6: PREM
Pin 7: AUDIO
Device and Signals Set-Up
VCC
IN
VCC
VCC
VCC
VCC
5K
1.5K
11.8k
100K
50k
10k
PIN CIRCUIT SCHEMATICS
The Audio Analyzer alternately turns ON and OFF its internal audio source to
make a measure of the Audio signal plus noise and then another measure of only
the noise.
The measurement is made using the internal CCIR468-2 Filter of the Audio
Analyzer together with the internal 30+/-2.0 KHz (60 dB/decade) Lowpass filters.
The AMFS demodulator uses a quasi-parallel demodulation as is the case in a
normal TV set. In this mode the Nyquist filter is bypassed and the video carrier
is used without added delay to effectuate intercarrier conversion. In this mode the
phase noise information fully cancels out and the true S/N can be measured.
Figure 3. Pin Schematics
Audio Signal to Noise
audio
ASN dB
(
)
=
Pin 8: SPLLFLT
Pin 10: VIDEO
Pin 14: RFOV
Pin 15: PLLFLT
Measurement Set-Up
20
Pin 13: RF
×
log
(
Signal
CC
IN
OUT
+
VCC
VCC
Noise
VCC
VCC
5K
VCC
2K
Application Specific Products
500
75
VCC
10K
VCC
)
Freescale Semiconductor
⁄
(
Noise
100
10K
)